Now that the ten-year effort to take stock of the diversity of life in the oceans came to a triumphant end late last year, researchers involved in the Census for Marine Life are reflecting on the project's shortcomings.

Tiny fossil tracks embedded in a California rock formation that was once part of an ancient river may be evidence that freshwater ecosystems arose around 100 million years earlier than what is generally believed.

There's good, stem cell-related news for another organ this week -- the lung. Researchers say they have found lung stem cells, which may hold therapeutic value for repairing damaged respiratory tissue, according to a study published this week in the New England Journal of Medicine (NEJM).